U.S. patent application number 11/175753 was filed with the patent office on 2006-03-16 for excavator and a machine for material transfer.
Invention is credited to Dirk Asam, Rolf Mieger, Roland Wachter, Bernd Wager.
Application Number | 20060053666 11/175753 |
Document ID | / |
Family ID | 35033735 |
Filed Date | 2006-03-16 |
United States Patent
Application |
20060053666 |
Kind Code |
A1 |
Asam; Dirk ; et al. |
March 16, 2006 |
Excavator and a machine for material transfer
Abstract
The invention relates to an excavator or to a machine for
material transfer comprising an element movable via at least one
hydraulic cylinder. In accordance with the invention, one or more
hydraulic cylinders are additionally hinged to the element, with
the additional hydraulic cylinder(s) being connected to one or more
hydraulic accumulators.
Inventors: |
Asam; Dirk; (Ulm, DE)
; Mieger; Rolf; (Kirchdorf, DE) ; Wachter;
Roland; (Oberroth, DE) ; Wager; Bernd;
(Kirchdorf, DE) |
Correspondence
Address: |
DILWORTH & BARRESE, LLP
333 EARLE OVINGTON BLVD.
UNIONDALE
NY
11553
US
|
Family ID: |
35033735 |
Appl. No.: |
11/175753 |
Filed: |
July 6, 2005 |
Current U.S.
Class: |
37/443 |
Current CPC
Class: |
E02F 9/2217 20130101;
F15B 1/024 20130101; F15B 21/14 20130101 |
Class at
Publication: |
037/443 |
International
Class: |
E02F 3/32 20060101
E02F003/32 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 7, 2004 |
DE |
10 2004032868 . 4 |
Claims
1. An excavator or a machine for material transfer comprising an
element movable via at least one hydraulic cylinder, and at least
one hydraulic cylinder additionally hinged to the element, the
additional hydraulic cylinder being connected to one or more
hydraulic accumulators.
2. An excavator or a machine for material transfer in accordance
with claim 1, wherein the element is a boom or shaft of an
excavator or a machine for material transfer.
3. An excavator or a machine for material transfer in accordance
with claim 1, wherein the additional hydraulic cylinder(s) are
arranged between or outside one or more hydraulic cylinders which
serve the movement of the element.
4. An excavator or a machine for material transfer in accordance
with claim 1, wherein the additional hydraulic cylinder(s) is/are
connectable to the main hydraulic circuit of the excavator or
machine for material transfer via a switchable valve.
5. An excavator or a machine for material transfer in accordance
with claim 1, wherein, with equipment consisting of a plurality of
elements, a plurality of additional hydraulic cylinders are
connected to one another and are connected to a hydraulic
accumulator.
6. An excavator or a machine for material transfer in accordance
with claim 1, wherein one of the two hydraulic cylinders present is
connected to one or more hydraulic accumulators.
7. An excavator or a machine for material transfer in accordance
with claim 2, wherein the additional hydraulic cylinder(s) are
arranged between or outside one or more hydraulic cylinders which
serve the movement of the element.
8. An excavator or a machine for material transfer in accordance
with claim 7, wherein the additional hydraulic cylinder(s) is/are
connectable to the main hydraulic circuit of the excavator or
machine for material transfer via a switchable valve.
9. An excavator or a machine for material transfer in accordance
with claim 2, wherein the additional hydraulic cylinder(s) is/are
connectable to the main hydraulic circuit of the excavator or
machine for material transfer via a switchable valve.
10. An excavator or a machine for material transfer in accordance
with claim 3, wherein the additional hydraulic cylinder(s) is/are
connectable to the main hydraulic circuit of the excavator or
machine for material transfer via a switchable valve.
11. An excavator or a machine for material transfer in accordance
with claim 10, wherein, with equipment consisting of a plurality of
elements, a plurality of additional hydraulic cylinders are
connected to one another and are connected to a hydraulic
accumulator.
12. An excavator or a machine for material transfer in accordance
with claim 2, wherein, with equipment consisting of a plurality of
elements, a plurality of additional hydraulic cylinders are
connected to one another and are connected to a hydraulic
accumulator.
13. An excavator or a machine for material transfer in accordance
with claim 3, wherein, with equipment consisting of a plurality of
elements, a plurality of additional hydraulic cylinders are
connected to one another and are connected to a hydraulic
accumulator.
14. An excavator or a machine for material transfer in accordance
with claim 4, wherein, with equipment consisting of a plurality of
elements, a plurality of additional hydraulic cylinders are
connected to one another and are connected to a hydraulic
accumulator.
15. An excavator or a machine for material transfer in accordance
with claim 7, wherein, with equipment consisting of a plurality of
elements, a plurality of additional hydraulic cylinders are
connected to one another and are connected to a hydraulic
accumulator.
16. An excavator or a machine for material transfer in accordance
with claim 8, wherein, with equipment consisting of a plurality of
elements, a plurality of additional hydraulic cylinders are
connected to one another and are connected to a hydraulic
accumulator.
17. An excavator or a machine for material transfer in accordance
with claim 9, wherein, with equipment consisting of a plurality of
elements, a plurality of additional hydraulic cylinders are
connected to one another and are connected to a hydraulic
accumulator.
18. An excavator or a machine for material transfer in accordance
with claim 10, wherein, with equipment consisting of a plurality of
elements, a plurality of additional hydraulic cylinders are
connected to one another and are connected to a hydraulic
accumulator.
19. An excavator or a machine for material transfer in accordance
with claim 18, wherein one of the two hydraulic cylinders present
is connected to one or more hydraulic accumulators.
20. An excavator or a machine for material transfer in accordance
with claim 2, wherein one of the two hydraulic cylinders present is
connected to one or more hydraulic accumulators.
Description
[0001] The invention relates to excavators and to machines for
material transfer comprising an element movable via at least one
hydraulic cylinder.
[0002] With excavators and machines for material transfer such as
excavators, wheel-mounted loaders and similar plant, a boom and/or
a shaft are moved e.g. via two parallel hydraulic cylinder pairs.
In the case of an excavator, an attachment tool is then attached to
the shaft and the good to be loaded is transferred with it. Both
the boom and the shaft and the attachment tools naturally have
masses. This means that only a small part of the energy used for
the lifting work benefits the lifting of the load. The much greater
part must be used for the lifting of the equipment and of the
attachment tool.
[0003] A detail of an excavator and of machines for material
transfer in accordance with the prior art is shown by way of
example in FIG. 1. It is an excavator in the present case. A boom
12 is hinged to a rotating deck 10 of an excavator here and is
movable via two hydraulic cylinder pairs 14. The hydraulic cylinder
pairs are connected together, as can be seen from the hydraulic
circuit diagram in accordance with FIG. 1a.
[0004] Some first efforts have already been made to recover the
energy expended in the lifting work of the equipment and of the
attachment tool in an energy recovering system. For this purpose,
it was attempted, for example in DE 102 56 442 A1 and DE 103 15 071
A1, to feed hydraulically stored energy into the main hydraulic
circuit. However, this is only successful with limitations since
the infeed pressure must always be larger than the system pressure
in the main circuit.
[0005] It is therefore the object of the present invention to
provide an excavator or a machine for material transfer in
accordance with the preamble of claim 1 in which a large part of
the energy expended for the lifting of the equipment and of the
attachment tool can, where possible, be stored for successive work
cycles.
[0006] This object is solved in accordance with the invention in
that, in addition to the at least one hydraulic cylinder present
for the movement of the movable elements, one or more additional
hydraulic cylinders are hinged to the element to be moved, with the
additional cylinder(s) being connected to one or more hydraulic
accumulators of their own. These additional hydraulic cylinders can
be arranged parallel to the already present at least one hydraulic
cylinder, but can also be attached at a different position. In
accordance with the invention, the additional hydraulic cylinders
do not engage in the hydraulic system, but are connected on the
piston side with a hydraulic accumulator which can consist of a
piston accumulator or a bladder accumulator.
[0007] Advantageous aspects of the present invention result from
the subordinate claims dependent on the main claim.
[0008] The element to be moved can accordingly be a boom or a shaft
of the excavator or of the machine for material transfer.
[0009] The additional hydraulic cylinder(s) can be arranged between
two hydraulic cylinders which serve to move the element, i.e. the
boom or the shaft.
[0010] In accordance with the invention, the accumulator is loaded
on the downward movement of the equipment. The stored energy then
in turn supports the upward movement of the equipment. The
equipment weight can hereby be compensated at least partly. The
same work is carried out via the, for example, three cylinders now
present instead of the two previously present as was previously
carried out by the two hydraulic cylinders connected in the
hydraulic circuit.
[0011] In accordance with a particularly advantageous embodiment of
the invention, the additional hydraulic cylinder(s) can be
connectable to the main hydraulic circuit of the excavator or
machine for material transfer via a switchable valve. For example,
for the case that the storage system breaks down, the third
cylinder can thus be switched into the main hydraulic circuit via a
valve so that the machine is not down and can carry out its work
without a problem.
[0012] Furthermore, with a multi-element equipment and on the
provision of more than one additional hydraulic cylinder, the
number of additional hydraulic cylinders can advantageously be
connected among one another. For example, on the downward movement
of the boom, the additional hydraulic cylinder of the shaft can
thus be fed such that the shaft is supported on extension and vice
versa.
[0013] The solution of the initially presented object in accordance
with the invention results in a series of advantages: The
previously used main hydraulic cylinders can thus be dimensioned
smaller. Less energy from the diesel engine is necessary overall
for the lifting. Higher working speeds are possible. The engine can
theoretically have less power or, if it has a higher power, it can
work in the part load range. Less energy has to be removed via the
radiator overall. The machine efficiency can be considerably
increased. The fuel consumption can thus be lowered. This in turn
results in a lowering of operating costs.
[0014] Moreover, the bearing strains of the hydraulic cylinders can
also be distributed onto six bearing positions instead of the usual
four. Due to the provision of accumulator(s) of its/their own for
the additional hydraulic cylinder(s), an active feeding into the
main hydraulic circuit is not necessary. No complex hydraulic
connections are thereby necessary.
[0015] The processes of feeding energy into the additional
hydraulic cylinder(s) are possible at any pressure level. No
consideration has to be made of the pressure level of the main
hydraulic circuit here. Finally, system redundancy is given by
switching the additional hydraulic cylinder(s) over to the main
hydraulic circuit.
[0016] Further features, details and advantages of the invention
result from the embodiments shown in the drawing. There are
shown:
[0017] FIG. 1: a detail view of a part of an excavator or of a
machine for material transfer in accordance with the prior art;
[0018] FIG. 2: a representation in accordance with FIG. 1 in
accordance with an embodiment variant of the present invention
(including the hydraulic circuit diagram); and
[0019] FIG. 3: a schematic hydraulic circuit diagram of a variant
of the embodiment in accordance with FIG. 2.
[0020] A detail of a hydraulic excavator is shown with reference to
FIG. 2 by way of example for an excavator and machines for material
transfer. Here, a boom 12 is pivotably hinged to a rotating deck
10, with the pivoting up and down of the boom 12 taking place via
hydraulic cylinders 14. In addition to the hydraulic cylinders 14,
an additional hydraulic cylinder 16 is arranged centrally. It can
be seen from the hydraulic circuit diagram in accordance with FIG.
2a that the hydraulic cylinders 14 are connected to one another in
a similar manner to that already known from the prior art (cf. FIG.
1a). In addition to the hydraulic cylinders 14, an additional
hydraulic cylinder 16 is provided whose piston side 18 is connected
to a hydraulic accumulator 20 which can, for example, be a piston
accumulator or a bladder accumulator.
[0021] As can be seen from the hydraulic circuit in accordance with
FIG. 2a, the additional hydraulic cylinder 16 is independent of the
hydraulic cylinders 14. The hydraulic. cylinder 16 serves the
purpose of the hydraulic fluid being displaced in the direction
toward the hydraulic accumulator 20 by the piston 22 on a downward
movement of the equipment. The energy is stored here until the boom
12 should again be moved upwardly. Here, the energy stored in the
accumulator 20 is released again by means of the additional
hydraulic cylinder 16 so that a large part of the mass force of the
boom and of the shaft or equipment suspended thereon is compensated
and no longer has to be expended by the hydraulic cylinders 14.
[0022] In the hydraulic circuit diagram in accordance with FIG. 3,
there is a basically similar embodiment variant as in the hydraulic
circuit diagram in accordance with the embodiment variant of FIG.
2a. Here, however, a selective connection with the main hydraulic
circuit, via which the hydraulic cylinders 14 are supplied, is
possible via corresponding switch valves 22 and 24 for the
additional hydraulic cylinder 16, which is here likewise connected
to a hydraulic accumulator 20. The additional hydraulic cylinder 16
can therefore be connected into the main hydraulic circuit
depending on the position of the valves 22 and 24. This may, for
example, be desired when the accumulator 20 is defective and when
the hydraulic excavator should continue to work continuously
despite this defect until it can be repaired.
* * * * *